In a principal aspect, the present invention relates to a multipart die for forming a metal clip into a substantially fixed diameter, helical configuration on a workpiece.
Velarde, in a pending patent application, Ser. No. 101,171, filed Dec. 7, 1979, discloses an improved multipart die assembly for forming a closed, helical clip. This die assembly is utilized to affix a metal clip about a workpiece so that the metal clip forms a tight circular but overlapped band on the workpiece. It is particularly important to form the metal clip in a substantially uniform helix, or "circular profile" or "circular form" as will be described subsequently, on the workpiece in order to prevent leakage or slippage of the workpiece from the clip.
The Velarde application discloses a multipart die which includes a base member for engaging the crown or shoulder of a clip and spaced swinging arms which engage the legs or tips of a clip. These members move uniformly to shape the clip in a circular form about the workpiece.
While such a die assembly works in a satisfactory manner, an improved clip forming die has been sought which will achieve more uniform and consistent control of the formation of the clip. These efforts resulted in the development of the present invention.